Engine



March 7, 1944. M CQBURN 2,343,748

ENGINE Filed Nov: 24, 1942 Patented Mar. 7, 1944 UNITED STATES ersmorrlcs Application November 24, 1942, Serial No. 466,751

1 Claim.

This invention relates to fuel ignition for internal combustion enginesoperating on the Diesel principle. Pistons of engine soperating on thisprinciple are subjected to high temperatures, due to the highcompression of the fuel necessary for the ignition thereof, which undulyshortens the life of said pistons. It is, therefore, the primary objectof this invention to prolong the life of the pistons by removingtherefrom the duty of highly compressing the fuel to bring about theignition thereof, by providing a fuel compressing means for igniting thefuel which ignites the fuel compressed by the pistons at a much lowercompression ratio than heretofore.

With these and other objects in view as will be hereinafter moreapparent as the description proceeds, the invention consists in certainnovel features of construction, combination and arrangement of parts aswill be hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had tothe following description and accompanying drawing, in which The figureis a fragmentary vertical sectional view showing a portion of an engineoperating on the Diesel principle equipped with a fuel igniting meansconstructed in accordance with the present invention.

Referring in detail to the drawing, the numeral indicates a, fragmentaryportion of an internal combustion engine operating on the Dieselprinciple. The means for admiting the fuel and the exhausting thereoffrom the engine is'not shown as any of the standard types of fuelinjection and exhaust means may be employed.

The main cylinder of the engine is indicated by the character 6 andreciprocally mounted therein is a main piston I connected to the crankshaft 8 by a connecting rod 9. The firing chamber of the cylinder isdesignated by the character III. A port II is provided in the cylinder 6extending from the exterior thereof to the firing chamber. This port IIis provided for the purpose of adapting the present invention to theengine.

An auxiliary cylinder I2 is mounted on the cylinder 6 in any suitablemanner and is provided with connected fuel passages I3 and I4 whichconnect with the port II of the engine 5. An auxiliary piston I5 isslidable in the cylinder l2 and is connected to the crank shaft 8 by aconnecting rod I6. The .auxiliary piston I5 travels in unison with thepiston I of the engine. The auxiliary cylinder I2 has a chamber IIformed in its upper end connecting with the cylinder I2 directly abovethe piston by a port l8 in the form of a valve seat. The chamber I1 isin direct communication with the fuel passage I3.

A spring operated valve I 9 controls the port I8. A housing 20 ismounted on the auxiliary cylinder and slidably supports the valve l9 bybeing provided with an apertured plug 2| threaded in the housing andproviding a seat for a coil spring 22 bearing against the collar 23 onthe stem of the piston. The spring 22 acts to hold the valve against anycompression within the cylinder I2 created by the piston I5. A lug 24 isformed on the upper end of the piston l5 so that when the piston nearsits uppermost posi tions, the lug 24 engages the valve and unseats thelatter to open the port IS. The passage It connects with the cylinder I2and is normally closed thereto by the piston I5, that is, when thepiston is in positions other than its lowermost position in the cylinderl2. When the piston I5 is in its lowermost position in the cylinder I2,the fuel passage I4 is uncovered and thereby placed in directcommunication with the cylinder I2.

In operation, during the fuel intake stroke ofthe piston I and when saidpiston I reaches a position near to its lowermost position, the pistonI5 uncovers the fuel passage I4 permitting the fuel in the firingchamber I0 to enter the auxiliary cylinder. On the compression stroke ofthe piston I and the piston I5, the fuel in the auxiliary cylinder ishighly compressed to bring about spontaneous combustion thereof. As thepiston I5 nears its uppermost position, it opens the valve I9 allowingthe ignited fuel in the cylinder I2 to pass into the chamber ll throughthe passage I3 into the firing chamber I0 and ignite the fuel thereinfor action on the piston I during the latters working stroke. Thus itwill be seen that the piston I is relieved of the duty of highlycompressing the fuel in order to bring about spontaneous combustionthereof and consequently the compression ratio within the cylinder ofthe engine 5 may be lowered over that required in the conventional typeof Diesel engine and thus relieve the piston I of the excessive heatwhich the pistons of Diesel engines are subjected to, consequentlymaterially prolonging the life of the piston of the engine.

This invention has been described in connection with an engine operatingon the Diesel principle. However, an engine designed for electricignition may have the present invention adapted thereto for the ignitionof the fuel.

While I have shown and described the preierred embodiment of myinvention, it will be understood that minor changes in construction,combination and arrangement of parts may be made without departing fromthe spirit and scope of the invention as claimed.

Having thus described my invention, what I claim is:

In a Diesel type internal combustion engine, a main cylinder having afiring chamber and port connecting therewith and leading exteriorly ofsaid cylinder, a main piston in said cylinder, a crank shaft connectedto said piston, an auxiliary cylinder mounted on the main cylinder andhaving connected fuel passages communicating with said port, saidauxiliary cylinder having a chamher in direct communication with one ofthe fuel passages and the other fuel passage having direct communicationwith the auxiliary cylinder, a valve mechanism for opening and closingsaid last-named chamber to said auxiliary cylinder, an auxiliary pistonin the auxiliary cylinder and connected to the crank shaft for movementin unison with the main piston to control fuel from the firing chamberof the main cylinder into the auxiliary cylinder and for compressing andigniting the fuel in the auxiliary cylinder, and a lug on the auxiliarypiston to unseat the valve to allow the ignited fuel to enter thesecond-named chamber and pass into the firing chamber by way of one ofthe passages and said port on the power stroke of the main piston.

MERTON A. COBURN.

